This invention relates to personal mobile communication devices and corresponding small handheld apparatuses designed for data acquisition and communication.
There exist prior art personal communication devices and/or mobile organizers, such as notebook microcomputers or similar apparatuses which are small, lightweight, portable workstations operated in one's hand and/or lap. Such a personal device can be equipped with a number of accessories and application programs offering service functions according to needs.
It is known, for example, systems of the type disclosed in the U.S. Pat. No. 5,475,441 (Parulski et al.) wherein a separate camera is connected via a flexible or fixed connection wire to a portable computer. From the user's point of view, this kind of a system is too laborious: the user has to carry along two separate apparatuses and possibly a connection cable, too. Such a camera cannot remain attached to the host device all the time because it is attached to the host device by means of an electrical connector, thus being highly susceptible to impacts or dropping.
It is also known to build a camera inside a mobile communication device. Such an arrangement is disclosed e.g. in the Japanese patent document 06268582A. In the system described in said document the camera is an integral part of the communication device. The system comprises a camera unit, which reads picture information in digital format, a mobile communication unit, which handles the radio connection, a bus, to which the camera unit and the mobile communication unit are connected, and a control unit, which controls the operation of the camera unit and the mobile communication unit. This kind of an arrangement eliminates most of the disadvantages of the system described above, but the disadvantage here is that the camera is integrated: the buyer has to pay for the camera unit even if he did not need it. In addition, the camera unit can only be used in connection with the mobile communication device to which it is integrated.
A Finnish patent application 942334 (Nokia Mobile Phones Ltd.) discloses a system wherein a camera built on a PCMCIA card can be connected to a mobile communication device. A disadvantage of such a system is the extrinsic quality of the PCMCIA card camera: it is attached to a connector on the side of the host device, thereby making the host device bigger and altering its appearance. Furthermore, an impact may cause the camera to come off the host device. In addition, the construction of the PCMCIA camera described in said application is complex: it includes, among other things, a picture-processing unit for the processing of pictures by the camera card.
An object of the invention is to provide a system for personal data acquisition and communication with characteristics easily modified by the user. Another object of the invention is to provide a system to which new functions and properties can be added even after the host device has been completed. A further object of the invention is to provide a system in which the host device constitutes an integral whole even when the expansion card is connected to the host device. A yet further object of the invention is to provide a system which, in addition to audio and text-based communication, facilitates visual communication.